Machine tool slideway and method of making the same



` W. W. POTTER .Filed June 29, 1932 INVENTOR VMM ATTORNEY MACHINE TOOL SLIDEWAY AND METHOD OF MAKING THE SAME Patented sept. 17, 1935 UNITED STATES PATEN'r OFFICE MACHINE TOOL SLIDEWAY AND METHOD OF MAKING THE SAME 4 Claims.

My invention refers particularly to slideways for machine tools, and to illustrate or exemplify it, I will use the case of its embodiment in the turret slide of a turret lathe. I do not limit myself, however, to this particular application of it, since my invention consists in whatever is described by or is within the terms or scope of the appended claims.

Where it is desirable to have one body slide upon another with maximum rigidity and accuracy of alignment, for example as in the case of machine tools, it has been the custom to provide two surfaces, scraped or ground to the requisite degree of accuracy, and. these surfaces have usually been of cast iron. To add to the length of their life, these bearing surfaces have been made of hardened steel. There is a hardened steel strip on the base and a contacting steel strip on the slide. With this construction, it is difficult to grind the contacting surfaces to a proper degree 'of accuracy, as the bearing surface is longitudinal of the grain, or fibers, of these steel strips, and holding down straps must be scraped into position after the original bearing has been machined.

By my invention, I provide a construction free of these objections and one that results in a simple and effective bearing and one by which original alinement may be easily secured. The bearing surface on one element or member, at least, will be across the ends of the fibers of the steel. This gives long life and enables the holding down straps to berst set up without any laborious and costly alining operation.

` In the drawing:-

Fig. 1 is a side elevation partially in section of a turret slide embodying my invention;

Fig. 2 is an end elevation partially in section.

The turret lathe base, I0, and the turret slide, II, are or may be of usual, or conventional construction, and need no special description. Upon the top of base, I0, at opposite sides are fastened horizontal hardened steel strips, I2, which are ground flat and true with-each other. Secured to the slide, above each strip, are a seriesof hardened steel plugs, I3, whose bottom faces constitute the sole bearing contact between slide and base. These plugs are inserted in cored holes I4, in the slide; are adjusted each by a screw I5, as hereinafter explained; and are then Vfirmly fixed in position by pouring a molten metal, expansible upon cooling (such as type metal), into the hole I4, through port, I6. The hardened plugs, I3, are ground perfectly flat upon faces, I'I, to form vthe bearing.V The slide is' held down on the base, I II, by straps, I8 and I 9, bolted to the slide by cap screws 20, and these straps respectively overlap lips 2| and 22, on base, I0.

I first attach the hardened steel strips to the base I grinding them on the surface after they are fastened to the base so they are perfectly flat and true with each other. At the same setting that I grind these surfaces, I also machine the lips 2I and 22, on the base I0, so that they are perfectly parallel with the surfaces of strips II. I then place the turret slide with the plugs 5 I3, inserted in the holes I4, securely bolting the straps I8 and I9 to the slide. Then by means of elevating screws 23, that bear at one end against the top of base, I0, I raise the slide I I, until straps I8 and I9, bear with the proper pressure on the 101.

lips 2| and 22, of the base. I next set up screws I5, until surfaces I'I, of plugs I3 bear evenly on the surface of strips I I and then pour the molten expansible metal into the holes I4, through port I6. This metal, upon cooling, forms a filling 24, that rinly secures plugs I3 in their adjusted position. Finally screws 23 are removed from the slide.

What I claim isz- 1. A bearing having contacting slides at least one of which has its bearing surface across the grain of the metal the contacting surf aces of such slides being extended in the direction of sliding movement, one of such surfaces being continuous and the other being composed of portions that 25 are spaced apart in the direction of sliding movement. 2. A method of constructing machine tool slideways which includes the acts of truing parallel slide surfaces on the machine base, adjustably face, and a member movably mounted thereon which has a plurality of spaced plugs with ends exposed for contact with the bearing surface of said strip and means for permanently fixing said plugs in a previously adjusted position with their ends in contact with the strip.

4. A bearing for machine members, one being a at surface support for the other which is slidable thereon, said bearing comprising opposing slide surfaces and means for holding at least one of such slide surfaces in a permanently fixed position relative to the other, comprising a cavity opening towards the other slide surface from which projects a part having the opposing slide surface with the latter exposed on the outside of said cavity, the cavity being larger than the 5 5 part therein and a metal ller in the 'cavity in holding contact with surfaces of said part in the cavity and with the cavity walls.

WILLIAM WALLACE POTTER. 

